Is It Bad to Sleep In? Weekend 'Social Jet Lag' May Cause Heart Disease, Study Says

Nobel Prize for Medicine awarded to sleep scientists. Reuters

Many of us don't get enough sleep. The Centers for Disease Control found in 2016 that one in three Americans is not getting the recommended seven hours of shut-eye on a regular basis. But just because we may be going to bed late and waking up early during the workweek doesn't mean we should sleep in after late nights out on the weekend to make up for it. According to a study by Sierra Forbush at the University of Arizona, for every hour of weekly "social jet lag," there is an 11 percent increase in the chance a person will suffer from heart disease.

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Now, what is social jet lag, you ask? It is essentially the discrepancy between when your body wants to sleep and when you actually do. So if on a weekday you typically go to bed at 12 a.m. and wake up at 7 a.m., but on weekends you go to bed at 1 a.m. and wake up at 8 a.m., that is one hour of social jet lag. "A lot of people will be waking up at 7 a.m. on weekdays, but going to bed later and sleeping in on the weekends to compensate," Forbush told New Scientist.

For her study, Forbush and her team analyzed responses to a survey about social jet lag given to 984 adults, ages 22 to 60, living in Pennsylvania. Forbush found the midpoint between when a participant would typically go to sleep and wake up, both on weekdays and on weekends. Insomnia and the duration of sleep was not taken into consideration, and the study did not examine whether the change in sleep patterns was causative. The researchers used data from Sleep and Healthy Activity, Diet, Environment, and Socialization (SHADES) study.

In addition to the increased chance of heart disease, the study found that social jet lag contributed to fatigue and worsened mood. So if you're wondering why you can never seem to get it in gear after sleeping in on a Saturday or Sunday morning, social jet lag is to blame.

Those who recorded an hour of social jet lag were 22 percent more likely to rate their health as good but not excellent, and 28 percent were more likely to rate it as fair or poor.

In 2012, a study conducted by Till Roenneberg of the University of Munich's Institute of Medical Psychology found that the body mass index of overweight people rose as they experienced more social jet lag, and that high social jet lag tripled the likelihood that a person was overweight. This could cause an increase in the chances of contracting not only heart disease but diabetes and other diseases as well.

"With social jet lag, we're forced to eat at times when the body doesn't want to eat, or isn't prepared for digesting food properly," Roenneberg told CNN. "All these things coming together might influence the way you digest food and how you incorporate it into your body fat. The result is that you become overweight or obese."

"Physicians often tell people to think about their diet and exercise, but I think this offers an additional preventative strategy," Forbush says. "It's not just about getting enough sleep, but getting regular sleep. Ideally, you want to be going to bed and waking up at the same time every day of the week."

Though social jet lag, the sleep effect, is bad, it shouldn't be confused with the Beach Fossils song of the same name, which is good. It's on the band's new album, Somersault, which was released June 2 on Bayonet Records.